Abstract
Purpose: :
The aim of our study is to analyze regulatory T-cells (CD4+CD25+FOXP3+) and to test possible correlation with diisease progression in patients affected by primary open-angle glaucoma (POAG) and age-matched controls.
Methods: :
18 patients affected by POAG (14 males, mean age:75 +/- 9 yrs) and 15 age-matched controls (10 males, mean age: 76 +/- 8 yrs) with negative history for neurodegenerative, autoimmune diseases, cancer, viral infection were selected for the study. Disease progression was estimated in glaucoma patients by retrospectively measuring visual field deterioration (24/2 SITA standard, Humphrey Field Analyzer) over a 5-year interval (at least 2 fields / year). Rate of field progression was calculated by (a) regression vs time of MD as measured by Glaucoma Damage Probability Trend in GMS3 software and (b) regression vs time of the GHT clusters mean sensitivity. Upon enrolment, whole blood was sampled from each patient. Flow cytometric analysis was used to determine the CD4+CD25+FOXP3 lymphocyte population. After magnetic cell separation (MACS) of CD4+CD25-(Tresp) and Treg cells, the suppression function of Tregs was assessed using the in vitro suppression test (Treg suppression Inspector, Miltenyi Biotec).
Results: :
The median value of Tregs (%) in POAG patients was 5.55 and 4.40 in controls. The Mann Whitney Test showed a significant difference (p=0.027) between the two groups. No difference in the suppression activity of Tregs has been noted between the POAG and control groups (88 and 94% of suppression in the 1:1 co-colture, respectively). MD rate of progression (mean + st.dev) was 0,8+0,7 dB /year in glaucoma patients. The rate of MD progression was significantly correlated with the % Tregs in the individual patients (r = 0.574, p < 0.05).
Conclusions: :
Patients with POAG (a) express a higher amount of Treg (CD4+CD25+FOXP3) than age-matched controls, (b) the Tregs maintain their suppressive activity and (c) the Tregs level correlates with the 5-year visual field rate of progression.
Keywords: immunomodulation/immunoregulation • clinical (human) or epidemiologic studies: risk factor assessment • perimetry